Unsynchronized German Engines

[Curious_Joey]

This is my first post on the forum and I'm far from aircraft aficionado, but I do understand the general principal of engine synchronization on propeller planes. As far as I know, it's more of a general comfort issue to the passenger to have synced engines rather than anything aerodynamic.

My question comes from hearing a story about Rudolf Hess and his insane landing in Scotland. He was flying a Me-110 fighter bomber and bailed out when he thought he had been spotted by British fighters. The story came from the father & son who found Hess parachuting to the ground. They immediately knew he had to be German & came from a German plane because of the sound of its unsynchronized engines.

So here are my questions: How noticeable would it be just hearing a plane fly past synchronized vs not?

Is there any media files you can point out to help compare the difference?

I'm assuming from the story Allied air power must have used synchronized engines, otherwise they wouldn't have spotted the Jerry. Is this true? Did any allied aircraft of that period have engines that could have sounded the same way & not been synchronized?

What about aircraft in formation? Would just the sound of the engines be enough to determine it was a German? Wouldn't a bunch of planes create the same unsynchronized sound?

Thanks in advance for your help and indulging my curiosity!

 

[FLYBOYJ]

IIRC there were several early German twins that either weren't synchronized or had a poor sync system. I think it was also a tactic to overfly target areas out od sync as a terror function, especially at night.

 

[gumbyk]

You can sync the engines by ear from the cockpit. A lot of light twins don't have syncrophasers in them, and it is just a matter of fine adjustments on one engine to eliminate that beat frequency (the wha-wha sound that you get). In my training, we set the left engine and adjusted the right.

So it was either deliberately done, or pilots simply weren't told how to do it.

 

[DerAdlerIstGelandet]

When I go out and do engine runs, I have to test the synchronizers. Part of the test involves manually synchronizing the props by listening to them. Was kind of hard at first, but once you get the "ear" for it is pretty easy. It is a very distinctive "out of sync" sound (well duh...).

Of course this with Turboprop King Airs, but can't be much different.

 

[gumbyk]

When I go out and do engine runs, I have to test the synchronizers. Part of the test involves manually synchronizing the props by listening to them. Was kind of hard at first, but once you get the "ear" for it is pretty easy. It is a very distinctive "out of sync" sound (well duh...).

Of course this with Turboprop King Airs, but can't be much different.

No, its essentially the same, the cause is that the props are doing slightly different RPM. Its easier with piston engines as they are usually noisier!

 

[DerAdlerIstGelandet]

No, its essentially the same, the cause is that the props are doing slightly different RPM. Its easier with piston engines as they are usually noisier!

Yeap, exactly...

 

[Juha]

IMHO the Germans used unsyncronized engines over Britain because it was believed that it made the pinpointing their exact location by sound locators more difficult.